diff --git a/docs/guide/extensions.md b/docs/guide/extensions.md
index 8af8d27..0ab62da 100644
--- a/docs/guide/extensions.md
+++ b/docs/guide/extensions.md
@@ -13,7 +13,14 @@ Code style
- Do not use `yiisoft` in the namespaces.
- Do not use `\yii`, `\yii2` or `\yiisoft` as root namespace.
-- Use `vendor-name` as the root namespace.
+- Namespace should be `vendorName\type\uniqueName` or `vendorName\uniqueName` if type is hard to tell.
+
+Choosing unique namespace is important to prevent name collisions. Examples:
+
+- `samdark\wiki`
+- `samdark\modules\tester`
+- `samdark\modules\debugger`
+- `samdark\widgets\iconizedMenu`
Distribution
------------
diff --git a/extensions/mongodb/Session.php b/extensions/mongodb/Session.php
new file mode 100644
index 0000000..bd06a04
--- /dev/null
+++ b/extensions/mongodb/Session.php
@@ -0,0 +1,202 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\mongodb;
+
+use Yii;
+use yii\mongodb\Connection;
+use yii\mongodb\Query;
+use yii\base\InvalidConfigException;
+
+/**
+ * Session extends [[\yii\web\Session]] by using MongoDB as session data storage.
+ *
+ * By default, Session stores session data in a collection named 'session' inside the default database.
+ * This collection is better to be pre-created with fields 'id' and 'expire' indexed.
+ * The collection name can be changed by setting [[sessionCollection]].
+ *
+ * The following example shows how you can configure the application to use Session:
+ * Add the following to your application config under `components`:
+ *
+ * ~~~
+ * 'session' => [
+ * 'class' => 'yii\mongodb\Session',
+ * // 'db' => 'mymongodb',
+ * // 'sessionCollection' => 'my_session',
+ * ]
+ * ~~~
+ *
+ * @author Paul Klimov <klimov.paul@gmail.com>
+ * @since 2.0
+ */
+class Session extends \yii\web\Session
+{
+ /**
+ * @var Connection|string the MongoDB connection object or the application component ID of the MongoDB connection.
+ * After the Session object is created, if you want to change this property, you should only assign it
+ * with a MongoDB connection object.
+ */
+ public $db = 'mongodb';
+ /**
+ * @var string|array the name of the MongoDB collection that stores the session data.
+ */
+ public $sessionCollection = 'session';
+
+ /**
+ * Initializes the Session component.
+ * This method will initialize the [[db]] property to make sure it refers to a valid MongoDB connection.
+ * @throws InvalidConfigException if [[db]] is invalid.
+ */
+ public function init()
+ {
+ if (is_string($this->db)) {
+ $this->db = Yii::$app->getComponent($this->db);
+ }
+ if (!$this->db instanceof Connection) {
+ throw new InvalidConfigException($this->className() . "::db must be either a MongoDB connection instance or the application component ID of a MongoDB connection.");
+ }
+ parent::init();
+ }
+
+ /**
+ * Returns a value indicating whether to use custom session storage.
+ * This method overrides the parent implementation and always returns true.
+ * @return boolean whether to use custom storage.
+ */
+ public function getUseCustomStorage()
+ {
+ return true;
+ }
+
+ /**
+ * Updates the current session ID with a newly generated one.
+ * Please refer to <http://php.net/session_regenerate_id> for more details.
+ * @param boolean $deleteOldSession Whether to delete the old associated session file or not.
+ */
+ public function regenerateID($deleteOldSession = false)
+ {
+ $oldID = session_id();
+
+ // if no session is started, there is nothing to regenerate
+ if (empty($oldID)) {
+ return;
+ }
+
+ parent::regenerateID(false);
+ $newID = session_id();
+
+ $query = new Query;
+ $row = $query->from($this->sessionCollection)
+ ->where(['id' => $oldID])
+ ->one($this->db);
+ if ($row !== false) {
+ if ($deleteOldSession) {
+ $this->db->getCollection($this->sessionCollection)
+ ->update(['_id' => $row['_id']], ['id' => $newID]);
+ } else {
+ unset($row['_id']);
+ $row['id'] = $newID;
+ $this->db->getCollection($this->sessionCollection)
+ ->insert($row);
+ }
+ } else {
+ // shouldn't reach here normally
+ $this->db->getCollection($this->sessionCollection)
+ ->insert([
+ 'id' => $newID,
+ 'expire' => time() + $this->getTimeout(),
+ 'data' => '',
+ ]);
+ }
+ }
+
+ /**
+ * Session read handler.
+ * Do not call this method directly.
+ * @param string $id session ID
+ * @return string the session data
+ */
+ public function readSession($id)
+ {
+ $query = new Query;
+ $row = $query->select(['data'])
+ ->from($this->sessionCollection)
+ ->where([
+ 'expire' => ['$gt' => time()],
+ 'id' => $id
+ ])
+ ->one($this->db);
+ return $row === false ? '' : $row['data'];
+ }
+
+ /**
+ * Session write handler.
+ * Do not call this method directly.
+ * @param string $id session ID
+ * @param string $data session data
+ * @return boolean whether session write is successful
+ */
+ public function writeSession($id, $data)
+ {
+ // exception must be caught in session write handler
+ // http://us.php.net/manual/en/function.session-set-save-handler.php
+ try {
+ $expire = time() + $this->getTimeout();
+ $query = new Query;
+ $exists = $query->select(['id'])
+ ->from($this->sessionCollection)
+ ->where(['id' => $id])
+ ->one($this->db);
+ if ($exists === false) {
+ $this->db->getCollection($this->sessionCollection)
+ ->insert([
+ 'id' => $id,
+ 'data' => $data,
+ 'expire' => $expire,
+ ]);
+ } else {
+ $this->db->getCollection($this->sessionCollection)
+ ->update(['id' => $id], ['data' => $data, 'expire' => $expire]);
+ }
+ } catch (\Exception $e) {
+ if (YII_DEBUG) {
+ echo $e->getMessage();
+ }
+ // it is too late to log an error message here
+ return false;
+ }
+ return true;
+ }
+
+ /**
+ * Session destroy handler.
+ * Do not call this method directly.
+ * @param string $id session ID
+ * @return boolean whether session is destroyed successfully
+ */
+ public function destroySession($id)
+ {
+ $this->db->getCollection($this->sessionCollection)
+ ->remove(['id' => $id]);
+ return true;
+ }
+
+ /**
+ * Session GC (garbage collection) handler.
+ * Do not call this method directly.
+ * @param integer $maxLifetime the number of seconds after which data will be seen as 'garbage' and cleaned up.
+ * @return boolean whether session is GCed successfully
+ */
+ public function gcSession($maxLifetime)
+ {
+ $this->db->getCollection($this->sessionCollection)
+ ->remove([
+ 'expire' => ['$lt' => time()]
+ ]);
+ return true;
+ }
+}
\ No newline at end of file
diff --git a/tests/unit/extensions/mongodb/SessionTest.php b/tests/unit/extensions/mongodb/SessionTest.php
new file mode 100644
index 0000000..ac0d49a
--- /dev/null
+++ b/tests/unit/extensions/mongodb/SessionTest.php
@@ -0,0 +1,140 @@
+<?php
+
+namespace yiiunit\extensions\mongodb;
+
+use yii\mongodb\Session;
+use Yii;
+
+class SessionTest extends MongoDbTestCase
+{
+ /**
+ * @var string test session collection name.
+ */
+ protected static $sessionCollection = '_test_session';
+
+ protected function tearDown()
+ {
+ $this->dropCollection(static::$sessionCollection);
+ parent::tearDown();
+ }
+
+ /**
+ * Creates test session instance.
+ * @return Session session instance.
+ */
+ protected function createSession()
+ {
+ return Yii::createObject([
+ 'class' => Session::className(),
+ 'db' => $this->getConnection(),
+ 'sessionCollection' => static::$sessionCollection,
+ ]);
+ }
+
+ // Tests:
+
+ public function testWriteSession()
+ {
+ $session = $this->createSession();
+
+ $id = uniqid();
+ $data = [
+ 'name' => 'value'
+ ];
+ $dataSerialized = serialize($data);
+ $this->assertTrue($session->writeSession($id, $dataSerialized), 'Unable to write session!');
+
+ $collection = $session->db->getCollection($session->sessionCollection);
+ $rows = $this->findAll($collection);
+ $this->assertCount(1, $rows, 'No session record!');
+
+ $row = array_shift($rows);
+ $this->assertEquals($id, $row['id'], 'Wrong session id!');
+ $this->assertEquals($dataSerialized, $row['data'], 'Wrong session data!');
+ $this->assertTrue($row['expire'] > time(), 'Wrong session expire!');
+
+ $newData = [
+ 'name' => 'new value'
+ ];
+ $newDataSerialized = serialize($newData);
+ $this->assertTrue($session->writeSession($id, $newDataSerialized), 'Unable to update session!');
+
+ $rows = $this->findAll($collection);
+ $this->assertCount(1, $rows, 'Wrong session records after update!');
+ $newRow = array_shift($rows);
+ $this->assertEquals($id, $newRow['id'], 'Wrong session id after update!');
+ $this->assertEquals($newDataSerialized, $newRow['data'], 'Wrong session data after update!');
+ $this->assertTrue($newRow['expire'] >= $row['expire'], 'Wrong session expire after update!');
+ }
+
+ /**
+ * @depends testWriteSession
+ */
+ public function testDestroySession()
+ {
+ $session = $this->createSession();
+
+ $id = uniqid();
+ $data = [
+ 'name' => 'value'
+ ];
+ $dataSerialized = serialize($data);
+ $session->writeSession($id, $dataSerialized);
+
+ $this->assertTrue($session->destroySession($id), 'Unable to destroy session!');
+
+ $collection = $session->db->getCollection($session->sessionCollection);
+ $rows = $this->findAll($collection);
+ $this->assertEmpty($rows, 'Session record not deleted!');
+ }
+
+ /**
+ * @depends testWriteSession
+ */
+ public function testReadSession()
+ {
+ $session = $this->createSession();
+
+ $id = uniqid();
+ $data = [
+ 'name' => 'value'
+ ];
+ $dataSerialized = serialize($data);
+ $session->writeSession($id, $dataSerialized);
+
+ $sessionData = $session->readSession($id);
+ $this->assertEquals($dataSerialized, $sessionData, 'Unable to read session!');
+
+ $collection = $session->db->getCollection($session->sessionCollection);
+ list($row) = $this->findAll($collection);
+ $newRow = $row;
+ $newRow['expire'] = time() - 1;
+ unset($newRow['_id']);
+ $collection->update(['_id' => $row['_id']], $newRow);
+
+ $sessionData = $session->readSession($id);
+ $this->assertEquals('', $sessionData, 'Expired session read!');
+ }
+
+ public function testGcSession()
+ {
+ $session = $this->createSession();
+ $collection = $session->db->getCollection($session->sessionCollection);
+ $collection->batchInsert([
+ [
+ 'id' => uniqid(),
+ 'expire' => time() + 10,
+ 'data' => 'actual',
+ ],
+ [
+ 'id' => uniqid(),
+ 'expire' => time() - 10,
+ 'data' => 'expired',
+ ],
+ ]);
+ $this->assertTrue($session->gcSession(10), 'Unable to collection garbage session!');
+
+ $rows = $this->findAll($collection);
+ $this->assertCount(1, $rows, 'Wrong records count!');
+ }
+}
\ No newline at end of file